Bundles of rolls and method for production thereof

ABSTRACT

A bundle ( 8 ) of rolls made from a strip of insulation of a fibrous material, comprising several rolls, arranged side by side with the axes thereof parallel in several superimposed layers with a wrapping film wrapping each layer in a compressed state in a first direction perpendicular to the axes of the rolls and a sleeve enclosing the superimposed layers in a state with the layers compressed one against the other in a second direction (F 3 ) perpendicular to the axes of the rolls and perpendicular to the first direction and covering the first and second ends of the rolls of the bundle.

The present invention relates to a bundle of rolls formed of aninsulation strip made of a fibrous product having an initial density,said bundle comprising

-   -   several aforementioned rolls, each having an axis, a peripheral        surface and first and second ends, and being arranged one next        to the other with their axes parallel, in a number of superposed        rows,    -   a packaging film which covers at least said peripheral surface        of each roll of the insulation strip which, when wound up on        itself, has a density which is greater than said initial        density, and    -   a wrapping film which wraps each row of several rolls, in a        compressed state of the rolls against one another in a first        direction perpendicular to the axes of the rolls, and which        covers at least part of the peripheral surface of the rolls of        the row.

These bundles are in particular intended to be stacked and then covered,with a view to being stored and transported on various vehicles. Thefibrous product of the rolls may be, for example, glass wool or amineral wool. These are products with a low density which thereforeoccupy a large volume in the condition in which they are to be used, andthis represents a problem in respect of storage and transport.

Bundles such as this have been known for a long time, and these aredescribed for example in EP-B-0 220 980 and EP-B-0 524 062.

However, these known bundles have the drawback that the rows of rollshave a diabolo shape, since the compression effect is concentrated inthe center of the rolls. Once the bundles have been set upright in thevertical position, said bundles therefore require a greater storagesurface area. Moreover, when the bundles are stacked, stretch-wrappingof the stacked bundles has to be carried out, and this stretch-wrappingis superposed on the wrapping film which has already been applied toeach of the bundles, the strip used for this purpose partiallyoverlapping itself during the stretch-wrapping operation, which involvesexcessive use of packaging material.

Finally, once the strip of fibrous material has been wound up on itself,the rolls have a density value which is determined as a function of thediameter of the roll and of the quality of the wool which must satisfycertain physical properties once the roll has been unwound. Once thebundle has been produced, given the formation of empty spaces betweenthe rolls when they are arranged in stacked rows, the overall density ofthe bundle exhibits an appreciable loss with respect to the density ofthe product which had been acquired as the roll was wound up. In orderto obtain a bundle with a standard volume for transport and storage, noadjustment can be made with regard to the parameter represented by thediameter of the rolls, since this must be a fixed parameter.

Also known are bundles of cylindrical wound articles which are bundledin this form. The density of the material on which these articles arebased, such as paper, fabric, etc, cannot be modified during theformation of the bundles, and the cylindrical shape of the articles ismaintained throughout the process (cf., for example, U.S. Pat. No.5,129,211 and U.S. Pat. No. 6,021,890).

The object of the present invention is to overcome the problemsmentioned above and to develop a bundle of rolls formed of an insulationstrip made of a fibrous product, which is mechanically resistant and hasstable and standardized dimensions, and a simple and inexpensiveproduction method which makes it possible to produce such bundles.

To this end, the invention provides a bundle of rolls as mentioned inthe introduction, which furthermore comprises a sleeve which enclosesthe wrapped and superposed rows of rolls, in a compressed state of therows against one another in a second direction perpendicular to the axesof the rolls and perpendicular to said first direction, and which coversthe first and second ends of the rolls of the bundle and at least partof the peripheral surface of the rolls of a top row and of a bottom rowof said superposed rows of the bundle, the bundle thus formed having afinal density which is at least equal to 90%, preferably 95%, of saiddensity which is greater than the initial density.

The very particular advantage of this bundle is that the rolls arewrapped not just around their periphery but also over their entirelength, so that their ends are kept compressed by the sleeve and so thatthe rolls do not take on a diabolo shape which requires a greater palletsurface area and therefore a greater storage and transport surface area.The rolls become more resistant in the length direction, and thepackaging is better and more uniform the more the wrapping films and thesleeve cross over one another.

The two successive compressions in two perpendicular directions have theeffect of maintaining, in the bundled product, the density acquiredduring the winding of the rolls.

By virtue of the two successive compressions, the rolls advantageouslyacquire a square cross section which is rounded at the corners, and thisreduces the spaces between rolls to the strict minimum. The rolls arepressed against one another over almost all of their peripheral surfacewhich is deformed by the compressions.

Whereas, at present, the stacking of the rows of rolls means that thebundle produced loses a large part of its density on account of emptyspaces being created between the stacked rolls, the bundle according tothe invention which is compressed in two mutually perpendiculardirections and kept in this compressed state recovers this loss ofdensity. The bundles obtained are of a standard volume, substantiallyindependently of the diameters of the rolls and therefore of the lengthof strip which is wound up.

According to one advantageous embodiment of the invention, the sleeveextends over all of the first and second ends of all of the rolls of thebundle.

In this way, when the bundle is set upright so that the rolls arearranged vertically in order to stack several bundles, the rolls cannotbe in contact with a substrate, in particular a floor, or with theexternal atmosphere on their top side. They therefore do not run therisk of the wool being damaged as a result of contact with dirt ormoisture.

According to one improved embodiment of the invention, the packagingfilm, the wrapping film and/or the sleeve are made of a non-extensibleplastics material. The compression of the rows of rolls and of thebundle can thus be obtained and maintained by a single wrapping film andrespectively a single sleeve. Use will preferably be made of a highdensity polyethylene, for example.

The present invention relates not only to a bundle of rolls according tothe invention but also to a stack of such bundles, usually two butsometimes more.

The present invention also relates to a method for producing such abundle or stack of bundles.

To this end, the invention provides a method for producing bundles ofrolls according to the invention, which comprises

-   -   a winding-up of an insulation strip made of a fibrous product,        having an initial density, so as to form rolls having then a        density which is greater than said initial density,    -   a first wrapping of each roll with a packaging film which covers        at least their aforementioned peripheral surface,    -   the arrangement of several aforementioned rolls one next to the        other with their axes parallel to form rows,    -   a first compression one against the other of the rolls of each        row in a first direction perpendicular to the axes of the rolls,    -   a second wrapping with a wrapping film of each row of several        rolls, in a compressed state resulting from the first        compression, so as to cover at least part of the peripheral        surface of the rolls of the row,    -   a superposition of several rows of rolls thus wrapped, and    -   a second compression one against the other of wrapped and        superposed rows of rolls in a second direction perpendicular to        the axes of the rolls and perpendicular to said first direction,        said method furthermore comprising    -   a third wrapping with a sleeve of the wrapped and superposed        rows of rolls, in a compressed state resulting from the second        compression, so as to cover the two ends of the rolls of the        bundle and at least part of the peripheral surface of the rolls        of a top row and of a bottom row of said superposed rows of the        bundle, the bundle thus formed having a final density which is        at least equal to 90%, preferably 95%, of said density which is        greater than the initial density.

Other embodiments of bundles and stacks of bundles according to theinvention, along with other embodiments of the method according to theinvention, are given in the appended claims.

Other details and features of the invention will emerge from thedescription which is given below by way of non-limiting example and withreference to the appended drawings.

FIGS. 1 to 4 show a perspective view of the steps of a method forforming a bundle according to the invention, up to the stacking of therows of rolls.

FIG. 5 shows a schematic side view of the compression and wrapping witha sleeve of the stack of rows of rolls.

FIG. 6 shows a perspective view of the stack of rows of rolls in thecompressed state.

FIG. 7 shows a perspective view of a finished bundle of rolls accordingto the invention.

FIGS. 8 to 10 show a perspective view of the steps of setting uprightthe bundles according to the invention, stacking them and covering thestacked bundles.

In the various drawings, identical or similar elements bear the samereferences.

FIG. 1 schematically shows a known roll 1 formed of an insulation strip(24) made of a compressible fibrous product, such as glass wool ormineral wool. This roll has an axis 2, a peripheral surface 3 and twoend surfaces 4 and 5. During winding of the roll, the fibrous materialhas undergone a compression which is determined as a function of thephysical properties that the wool must have in the unwound state. Itsperipheral surface 3 has then been wrapped in a manner known per se witha packaging film (25). The roll which is formed thus has a given firstdensity and a given diameter d of the end surface. In the example shown,the aforementioned diameter d may for example vary from 380 to 500 mmand the rolls may have a width l of, for example, 1200 mm. This widthmay of course vary as a function of requirements.

The rolls 1 thus formed are arranged one next to the other with theiraxes parallel so as to form a row of rolls 6 (cf. FIG. 2). In theexample shown, the length L1 of the row is for example 1400 to 2000 mm.It will of course be understood that, depending on the diameter of theend surfaces 4 and 5 of the rolls 1, any suitable number of rolls may bearranged in rows, preferably three or four, as shown.

As shown in FIG. 3, this row 6 of rolls 1 is wrapped in a wrapping film7 after the rolls have been compressed one against the other in adirection shown by the arrows F1, which is perpendicular to the axes 2of the rolls. Following a compression force of around 1.5 tons forexample, the rolls have an oval cross section and the length L2 of thecompressed row becomes, in the example shown, 1330 mm. The wrapping film7 is preferably formed of a strip made of non-extensible plasticsmaterial, for example high density polyethylene, so that the wrappingfilm keeps the rolls of the row 6 in their compressed state. Veryadvantageously, the film 7 extends from one end to the other of therolls on part of their peripheral surface 3, leaving the end surfaces 4and 5 of the rolls free.

In a bundle according to the invention, several rows of rolls as shownin FIG. 3 are then stacked as shown in FIG. 4. It is possible to providefor stacking of any suitable number of compressed and wrapped rows ofrolls 6, for example three rows as shown. Twelve rolls are thus obtainedin the illustrated bundle 8, and for example nine rolls if each rowcomprises only three rolls. In the state shown in FIG. 4, the bundlehas, in the example illustrated, a width l of 1200 mm, a length L2 of1330 mm and a height h1 of 1600 mm.

All the production steps up to the formation of the bundle shown in FIG.4 are known in a very general manner in the prior art. By way ofexample, reference may be made more particularly to EP-B-0 220 980. Itwould of course also be possible to envisage other ways of forming sucha bundle, for example by pushing the stacked and compressed rows intothe opening of a preformed sheath.

It must be noted at this stage that, on account of the presence of emptyspaces 9 between the rolls and the rows of rolls in the bundle, thelatter exhibits a loss of density of 30% and sometimes more compared tothe density of a roll which has just been wound up.

It must also be noted that, in the bundles according to the prior art inwhich vertical compression does not take place, the diameter of therolls must always be fixed at the start if it is desired to obtain abundle which always has approximately the same volume. This represents adisadvantageous restriction when the various requirements of the usersmust be met, for example in terms of the length of strip in each roll.

As shown in FIG. 6, the bundle according to the invention comprises rowsof rolls which are stacked in a compressed state of the rolls oneagainst the other in a direction shown by the arrow F2. A compressionforce of around 2 tons may thus be applied. The direction F2 is not onlyperpendicular to the axis 2 of the rolls 1 but also to the direction ofthe first compression shown by the arrows F1 in FIG. 3. This secondcompression has the effect of eliminating the ovalization of the rolls,but also of eliminating for the most part the empty spaces 9 by givingthe rolls a square cross section which is rounded at the corners (cf.FIG. 6).

As shown in FIG. 7, a sleeve 10 covers the wrapped and superposed rowsof rolls in the compressed state which is thus obtained. This sleevecovers the end surfaces 4 and 5 of the rolls, by extending preferablyover the entirety of these surfaces. This sleeve, which isadvantageously made of a non-extensible plastics material such as highdensity polyethylene, keeps the rolls in their state of compressionwhich is obtained after the second compression. In the illustratedexample of embodiment, the bundle according to the invention shown inFIG. 7 has a width l of 1200 mm, a length L2 of 1330 mm and a height h2of 1200 mm. The obtained volume of the bundle is standard even if thediameter of the rolls used, and therefore the length of strip in eachroll, is variable. Moreover, the bundle according to the invention onceagain has a density which is equivalent to that obtained after windingof the rolls. The loss of density usually does not exceed 5%, and it mayeven be equal to or greater than that obtained after winding of therolls.

Advantageously, the width of the strip 1 may be variable withoutrequiring any modification of the method according to the invention,since the sleeve is applied over the length of the rolls.

In order to produce a bundle according to the invention as shown in FIG.5 from a known bundle as shown in FIG. 4, use may be made of varioussuitable means which are known per se to the average person skilled inthe art.

By way of example, an apparatus which can be used for this purpose isshown schematically in FIG. 5. The bundle of rolls shown in FIG. 4 isintroduced between two conveyors 11 and 12. The conveyor 11 is formed ofa belt rotating about a chassis which can be displaced upward anddownward in the direction of the double arrow F3 by means of a controlelement 13 of the type consisting of a motor/rack, a hydraulic orpneumatic ram, etc. The bundle is introduced while the conveyor 11 is inthe high position shown in broken line. The axes 2 of the rolls arearranged parallel to the direction of advance shown by the arrow F4.Once the bundle is located entirely between the two conveyors 11 and 12,the upper conveyor 11 is displaced downward so as to compress the bundleuntil the latter obtains the desired height value of the bundle.

In the illustrated example of embodiment, two strips of packagingmaterial 13 and 14 which are sealed end to end at 21 extend in front ofthe outlet of the conveyors 11 and 12. The end surfaces (which are stilluncovered) at one side of the rolls are pressed against these strips 13and 14 and entrain them from reels 15 and 16 in the direction of advanceF4. During this time, the bundle advances between two new conveyors 17and 18, which are the same distance apart as the conveyors 11 and 12when the conveyor 11 is in the low position. The bundle 8 is then passedentirely between the two conveyors 17 and 18 as shown in broken line. Atthis point, clamps 19 and 20, which can be moved back and forth in adirection shown by the double arrows F5 and F6, grip the strips 13 and14 one against the other. In the illustrated example of embodiment,these clamps in the clamped position make it possible to form twohorizontal seals, which are close to one another and parallel to oneanother, so as to close the sleeve, while at the same time sealing thetwo strips 13 and 14 end to end for the following bundle. These clampsalso have, between the two sealing elements, a means which makes itpossible to cut the elastic material between the two seals and to detachthe bundle, for example an electrically heated wire or a knife which isdisplaced in the transverse direction. The sleeve thus maintains theeffects of the second compression even when it exits from the conveyors17 and 18.

The person skilled in the art will understand that other suitable meansallow this compression and this wrapping to be carried out. For example,it would be possible to provide just one reel and one strip. Othermethods of sealing the strips 13 and 14 could be envisaged. Thedirection of advance of the bundles could be oblique or even vertical.

It would also be possible to envisage the advance of the strip withrespect to the bundle, so as to obtain the wrapping as shown in FIG. 7.

The bundle according to the invention is then, in a manner known per se,set upright so that the axes 2 of the rolls are arranged vertically. Ascan be seen in FIG. 8, neither the bottom end surfaces of the rolls northe top end surfaces are now in direct contact with the ground or withthe surrounding environment, and this represents a marked improvement interms of protecting the rolls against dirt and moisture.

FIG. 9 shows the stacking, known per se, of two bundles 8. The stack 22thus formed is highly resistant and protected on all its faces againstweather conditions and dirt. Finally, a cover 23 may also be providedwhich covers the whole stack, as shown in FIG. 10.

Tests were carried out using various rolls.

In the examples 1 to 8 according to the invention, the rolls arearranged in rows, each row being compressed, wrapped and then stacked,and the stacked rows undergo an additional compression and an operationof wrapping in a sleeve, as described above.

The results of the tests are shown in the table below.

Roll Bundle Density Density Rolls Rows Strip before after per per ExThickness Length Width Diameter winding winding row bundle Length HeightWidth Density 1 200 5000 1200 424 11.5 81.34 4 3 1330 1200 1200 86.47 2200 6500 1200 484 11.5 81.34 3 3 1330 1200 1200 84.30 3 180 4500 1200472 21 97.22 3 3 1330 1200 1200 95.92 4 180 3500 1200 416 21 97.22 4 31330 1200 1200 99.47 5 140 5500 1200 467 15 67.51 3 3 1330 1200 120065.13 6 140 4250 1200 410 15 67.51 4 3 1330 1200 1200 67.11 7 100 125001200 474 10.5 74.27 3 3 1330 1200 1200 74.01 8 100 9500 1200 414 10.574.27 4 3 1330 1200 1200 75.00

This table shows, on the one hand, the extremely high flexibility interms of the length of strip to be wound for the bundles according tothe invention and, on the other hand, the absence of any loss ofdensity, while the dimensions of the bundle remain perfectly standard.

It must be understood that the present invention is in no way limited tothe embodiments given above and that many modifications may be madethereto without departing from the scope of the appended claims.

1. A bundle of rolls formed of an insulation strip made of a fibrousproduct having an initial density, said bundle comprising severalaforementioned rolls, each having an axis, a peripheral surface andfirst and second ends, and being arranged one next to the other withtheir axes parallel, in a number of superposed rows, a packaging filmwhich covers at least said peripheral surface of each roll of theinsulation strip which, when wound up on itself, has a density which isgreater than said initial density, and a wrapping film which wraps eachrow of several rolls, in a compressed state of the rolls against oneanother in a first direction perpendicular to the axes of the rolls, andwhich covers at least part of the peripheral surface of the rolls of therow, characterized in that said bundle furthermore comprises a sleevewhich encloses the wrapped and superposed rows of rolls, in a compressedstate of the rows against one another in a second directionperpendicular to the axes of the rolls and perpendicular to said firstdirection, and which covers the first and second ends of the rolls ofthe bundle and at least part of the peripheral surface of the rolls of atop row and of a bottom row of said superposed rows of the bundle, thebundle thus formed having a final density which is at least equal to90%, preferably 95%, of said density which is greater than the initialdensity.
 2. The bundle as claimed in claim 1, characterized in that thefinal density of the bundle is greater than or equal to said densitywhich is greater than the initial density.
 3. The bundle as claimed inclaim 1, characterized in that, in the bundle, the rolls have a squarecross section which is rounded at the corners.
 4. The bundle as claimedin claim 1, characterized in that the wrapping film extends, on said atleast part of the peripheral surface of the rolls which it covers, fromthe first end of the rolls to the second end.
 5. The bundle as claimedin claim 1, characterized in that the sleeve extends over all of thefirst and second ends of all of the rolls of the bundle.
 6. The bundleas claimed in claim 1, characterized in that the packaging film, thewrapping film and/or the sleeve are made of a non-extensible plasticsmaterial.
 7. A stack of at least two bundles of rolls as claimed inclaim
 1. 8. The stack as claimed in claim 7, in which the rolls of eachbundle are arranged with their axes in the vertical position and thestack has a bottom surface and a top surface which are covered by anaforementioned sleeve.
 9. The stack as claimed in claim 7, characterizedin that it comprises a cover which surrounds said at least two stackedbundles.
 10. A method for producing a bundle of rolls as claimed inclaim 1, comprising a winding-up of an insulation strip made of afibrous product, having an initial density, so as to form rolls havingthen a density which is greater than said initial density, a firstwrapping of each roll with a packaging film which covers at least theiraforementioned peripheral surface, the arrangement of severalaforementioned rolls one next to the other with their axes parallel toform rows, a first compression one against the other of the rolls ofeach row in a first direction perpendicular to the axes of the rolls, asecond wrapping with a wrapping film of each row of several rolls, in acompressed state resulting from the first compression, so as to cover atleast part of the peripheral surface of the rolls of the row, asuperposition of several rows of rolls thus wrapped, and a secondcompression one against the other of wrapped and superposed rows ofrolls in a second direction perpendicular to the axes of the rolls andperpendicular to said first direction, characterized in that said methodfurthermore comprises a third wrapping with a sleeve of the wrapped andsuperposed rows of rolls, in a compressed state resulting from thesecond compression, so as to cover the two ends of the rolls of thebundle and at least part of the peripheral surface of the rolls of a toprow and of a bottom row of said superposed rows of the bundle, thebundle thus formed having a final density which is at least equal to90%, preferably 95%, of said density which is greater than the initialdensity.
 11. The production method as claimed in claim 10, characterizedin that the third wrapping comprises advancing the wrapped andsuperposed rows of rolls in a direction of advance which is parallel tothe axes of the rolls.
 12. The method as claimed in claim 11,characterized in that during this advance, a pressing of one of the endsof the rolls of the superposed rows against two strips of packagingmaterial which are sealed end to end, and a covering with these stripsof said one of the ends of the rolls and then of at least part of theperipheral surfaces of the rolls of said top and bottom rows, a joiningof the two strips by applying them along the other of the ends of therolls of the superposed rows, with the strips being sealed together, anda cutting of the sealed strips so as thus to form, on the one hand, asleeve which covers the superposed rows of rolls and, on the other hand,once again two strips of packaging material which are sealed end to end.13. The method as claimed in claim 10, characterized in that the thirdwrapping comprises advancing a strip of packaging material around thebundle of rolls, in a direction of advance which is parallel to the axesof the rolls, so as to form said sleeve.
 14. The method as claimed inclaim 11, characterized in that the aforementioned direction of advanceis horizontal and in that the method furthermore comprises, after saidthird wrapping, setting the bundle upright so that the axes of the rollsare arranged vertically, and so that each bundle has a bottom surfaceand a top surface which are covered by the aforementioned sleeve. 15.The method as claimed in claim 14, characterized in that it furthermorecomprises a stacking of at least two bundles of rolls so as to form astack having a bottom surface and a top surface which are covered by anaforementioned sleeve.
 16. The method as claimed in claim 15,characterized in that it furthermore comprises a covering of the stackof bundles of rolls.
 17. The method as claimed in claim 11,characterized in that, during the second compression, the rolls acquirea square cross section which is rounded at the corners.